i am going to show you where you need to upload your ringtones on your samsung infuse wireless android phone. its very easy, first you will need to have the ringtone in .wav format, it cannot be in MP3 because the system will not recognize it, there are alot of freeware utility software that you can convert from mp3 into .wav format

after you have your .wav format, connect your phone to your computer with your usb and select media.

go to the sd card and there you will see a folder called media, then go to audio, place your rigntones there in the media\audio\ directory